Conference paper
Accuracy Evaluation of Horizon Shading Estimation Based on Fisheye Sky Imaging
Photovoltaic Materials and Systems, Department of Photonics Engineering, Technical University of Denmark1
Department of Photonics Engineering, Technical University of Denmark2
Photovoltaic Materials and Systems, Department of Electrical and Photonics Engineering, Technical University of Denmark3
Department of Electrical and Photonics Engineering, Technical University of Denmark4
Measuring horizon shading and modeling available irradiance at a prospective site is necessary for accurate estimation of the energy yield of photovoltaic (PV) systems, as well as the expected operation and availability of PV powered products. Fisheye sky imaging is a relatively simple approach to characterize the surrounding horizon, however it's accuracy in estimating the shading loss on short timescales is not well quantified in the literature.
In this work we evaluate the shade irradiance loss estimation accuracy of a horizon shading model based on fisheye sky images compared to actual local irradiance measurements from the site of interest. The results show that small errors in he horizon line estimation can lead to high irradiance estimation errors, for short timescales.
However, these are mostly averaged out if the sampling period is 15 minutes or higher. The horizon shading maps obtained both with a commercial shading analysis tool, as well as self-calculated from raw fisheye images, tend to overestimating the direct beam shading and small relative errors are observed.
Furthermore, ground reflected irradiance has a great influence on vertical surfaces, which was not accounted for in this work.
Language: | English |
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Publisher: | IEEE |
Year: | 2021 |
Pages: | 2052-2059 |
Proceedings: | 48<sup>th</sup> IEEE Photovoltaic Specialists Conference |
Series: | Conference Record of the Ieee Photovoltaic Specialists Conference |
ISBN: | 1665419229 and 9781665419222 |
ISSN: | 01608371 |
Types: | Conference paper |
DOI: | 10.1109/PVSC43889.2021.9519063 |
ORCIDs: | Alvarez Mira, Daniel , Bartholomaus, Martin , Poulsen, Peter B. and Spataru, Sergiu V. |
Fisheye imaging Horizon shading SDG 7 - Affordable and Clean Energy Shading analysis Site assessment
Conferences Energy measurement Estimation error Imaging Loss measurement PV powered products Photovoltaic systems Tools actual local irradiance measurements commercial shading analysis tool direct beam shading expected operation fisheye imaging fisheye sky images fisheye sky imaging high irradiance estimation errors horizon line estimation horizon shading horizon shading estimation horizon shading maps horizon shading model modeling available irradiance photovoltaic power systems photovoltaic systems prospective site raw fisheye images reflectivity relatively simple approach shade irradiance loss estimation accuracy shading analysis shading loss short timescales site assessment solar cells sunlight surrounding horizon time 15.0 min